The general purpose of this project is to investigate the roles of autonomic nervous system (ANS) activity, attention, and information processing and their interrelationships in the pathology, etiology, and prognosis of psychiatric disorders. A second purpose is to determine biological and psychological processes related to ANS activity. ANS activity is assessed by peripheral measures, such as skin conductance, heart rate, and skin temperature. Subjects are tested under conditions of rest, presentation of tones, and performance on reaction time, mental arithmetic, two-flash discrimination, or tachistoscopic recognition tasks. Biological mechanisms influencing ANS activity and attention are investigated by testing the effects of drugs and other treatments and by correlating these variables with enzyme activity, neuropeptides, and levels of biogenic amines and their metabolites. Psychological determinants are investigated by correlating the results with personality, mood, and personal history questionnaires by information from interviews, and by the effects of procedural variations. Studies are being done on unmedicated patients with diagnoses of schizophrenia, affective disorder, obsessive compulsive disorder, anxiety-panic disorder, and autism to test the diagnostic specificity of patterns of ANS activity. Effects of state changes are studied in cases of multiple personality and in women in different phases of the menstrual cycle. Effects of pimozide, GHB, propanolol, prazosin, verapramil, and hemodialysis have been or are being studied in schizophrenics. Obsessive patients have been studied while taking clorgyline and clomipramine. The use of confirmatory factor analysis in data reduction and to improve quantification of ANS activity is being explored.